Apparatus for winding coils for stators of electrical machines

ABSTRACT

An apparatus for winding coils for stators of electrical machines having a former on which the coils are wound and which is made up of at least two portions movable radially towards and away from each other to vary the cross-section of the former between a large cross-section winding position, a small crosssection drawing-off position, and at least one intermediate cross-section winding position. A rod extending axially between the former portions is connected to these portions by a parallel linkage such that axial movement of the rod causes radial movement of the former portions. Stop members are movable into the path of axial movement of the rod and its associated parts to stop the rod at the intermediate position.

Droll United States Patent [1 1 Feb. 18, 1975 APPARATUS FOR WINDING COILS FOR STATORS OF ELECTRICAL MACHINES Inventor: Hans Droll. An der Rosenhelle 4,

6369, Niederdorfelden, Germany Filed: Dec. 14, 1972 Appl. No.: 314,964

[30] Foreign Application Priority Data Dec. 15, 1971 Germany 2162145 [52] US. Cl 242/7.09, 140/922, 242/7.l3, I 242/721 [51] Int. Cl B2lf 3/04, H02k 15/04, HOlf 41/06 [58] Field of Search 242/709, 72, 73, 72.1, 242/7.13, 7.14, 92.1; 140/922 [56] References Cited UNITED STATES PATENTS 2,143,315 l/1939 Hanson 140/922 2,514,251 7/1950 Moore et a1. 140/922 2,558,621 6/1951 Martilla 140/922 2,809,674 10/1957 Ward 140/922 2,989,263 6/1961 Smeets 242/721 3,166,104 l/l965 Foley, Jr. ct a1 140/922 Primary ExaminerBilly S. Taylor Attorney, Agent, or Firm-Larson, Taylor and Hinds [57] I ABSTRACT.

An apparatus for winding coils for stators of electrical machines having a former on which the coils are wound and which is made up of at least two portions movable radially towards and away from each other to v vary the cross-section of the former between a large cross-section winding position, a small cross-section drawing-off position, and at least one intermediate cross-section winding position. A rod extending axially between the former portions is connected to these 1 portions by a parallel linkage such that axial movement of the rod causes radial movement of the former portions. Stop members are movable into the path of axial movement of the rod and its associated parts to stop the rod at the intermediate position.

v 8 Claims, 7 Drawing Figures PATENTEUFI'IB1 8M5 3, 866,847

' sum 10F 4 PATENTED FEB! 8 I975 SHEH U 0F 4 BACKGROUND OF THE INVENTION This invention relates to the winding of coils for stators of electrical machines, and in particular, it relates to such an apparatus wherein the cross-section of the former can be varied between different winding positions as well as a smaller drawing-off position.

In the production of stators of electric machines, the coils, according to the customary process are wound on formers and then drawn into the stator. The same cross-section of the former is used for all coils of a certain stator which extend over the same angular area of the stator. Said former cross-section must be dimensioned such that the coils lyingfarthest outside in the stator can be drawn in without trouble and can be brought into their predetermined positions. However, the same cross-section is then too large for the radially inside coils since the so-called winding heads projecting beyond the front surfaces of the packet of metal plates of the stator are larger than in the case of the outside coils. Whenever several formers are available, this could be taken into consideration by the fact that the outside coils are wound on larger formers than the inside coils. If however, one operates with only one single former, thewinding heads of variable sizes cannot be avoided with the previously known devices.

Thus, there exists a need for a new and improved apparatus for winding coils so that coils of different sizes can be wound on the same former.

SUMMARY OF THE INVENTION Thus, it is a purpose of the present invention to provide a new and improved coil winding apparatus which will overcome the disadvantages of previous apparatus.

More particularly, it is a purpose of the invention to provide a winding apparatus with which it will be possible to wind coils or groups of coils with different diameters in the stator, the size depending on the position of the coil within the stator, and winding these coils successively on the same former so that after all of the coils are drawn off of the former and into the stator, the winding heads of the radially inner coils will project essentially as far beyond the front surface of the stator as those of the radial outer coils.

These purposes are achieved according to the invention by the fact that the former can be adjusted mechanically in several winding positions with variable cross-sections,as a result of which one will have the advantage that as a result of the variable widths of the coils obtained, after drawing the coils into the stator, the windingheads are better arranged and do not have to be formed with a major expenditure of power. The wound stators are lighter, and because of the flatter dimensions of the'housings the housing can also be kept smaller. All advantages are particularly applicable for larger stators with relatively deep grooves of, forexample, 30 mm and more. The insignificant effects of the variable coil diameters on the electric and magnetic characteristics of the stator are practically of no consequence, because all poles or phases are equally affected.

The adjustment of the former for a majority of variable winding cross-sections can be realized in different ways. In a preferred practical embodimenh't he former is divided in one or more axial planes and the portions of the former are movable along radial guides by means of levers articulated to an axially movable push rod, whereby the various winding positions are determined by several stops, movable selectively in the action position and cooperating with the push rod. It will of course be understood that besides this preferred arrangement 7 a large number of possibilities will be apparent to one positions can also be used.

Thus, it is an object of this invention to provide a new and improved arrangement for varying the crosssection ofa former in an apparatus for winding coils for electrical machines. I

It is another object of this invention to provide, in an apparatus of the type described, an arrangement for varying the cross-section of the former-including an axially moving'rod articulated to the portions of the former such that reciprocating movement of the rod causes radial outward and inward movement of the former portions.

It is another object of this invention to provide, in an apparatus of the type described, an axially movable rod articulated to the former portions such that axial movement of the rodvaries the cross-sectional area of the former, and including a power means for reciprocating the rod, and stop members operatively associated with said axial movement of the rod for limiting said axial movement to place said former at an intermediate cross-section winding position.

Other objects and the advantages of the invention will-become apparent from the detailed description to follow, together with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS There follows a detailed description of a preferred embodiment of the invention to be read together with the accompanying drawings which are provided merely for purposes of illustration.

FIG. 1 is a side elevational view of a coil winding apparatus according to the present invention.

FIGS. 2a, 2b, 2c and 2d are longitudinal sectional views through a portion of the apparatus of FIG. 1, and showing this apparatus in four different operating positions.

FIG. 3-is a partial longitudinal sectional view similar to FIGS. 2a-2d but greatly enlarged and showing only a portion thereof, this figure also being taken along line III-III of FIG. 4.

FIG. 4 is a simplified schematic end elevational view of a portion of FIG. 3 as viewed in the direction of the arrow IV of FIG. 3.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS:

Referring now to the drawings, like numerals are represented by like elements throughout the several views. The winding apparatus shown in a simplified manner in FIG. 1 has a former 12 mounted rotatably on the machine frame 10, which former obtains its rotating drive from an electric motor 14 via a transmission 16. The winding wire is supplied to the rotating former 12 by a wire guide, designated in its entirety by the numeral 18, for the purpose of winding of coils. During the winding, the former 12, which can comprise two or more portions, is expanded, and the parts of the former are then moved closer to each other so that the wound coils which now rest loosely on the former can be taken off easily. For the purpose of radial expansion or moving together of the portions of the former, each former portion is screwed to a slide member 20 by means of T- shaped grooves, which slide members are guided by means of a rod guide 22 on a face plate 24. Each former portion can be adjusted radially by means of an axially movable push rod 26 which is connected to the slide members 20 by links 28 and to the former portions by links 30, the links 28 and 30 associated with each former portion constituting a parallel linkage arrangement. In the case of longer formers, as FIG. 1 shows, additional links 30 can be articulated'to the portions of the former or with supporting means connected with them as well as with the push rod.26 for the support and parallel guidance of said portions of the for- The face plate 24 is connected firmly by way of a flange 32 with the driving shaft 34 (see FIGS. 2a-2d) which is driven by the motor 14 by way of the transmis sion 16. The front end of the push rod 26, visible in FIG. 1, with the links 28 and 30, rotates with the face plate 24 and the former 12.

As FIGS. 2ad show, the driving shaft 34 is developed as a hollow shaft. In these figures, the transfer of torque from the transmission 16 to the shaft 34 has been indicated only diagrammatically at 36.

The push rod 26 extends through the driving shaft 34 and is mounted in the latter. It projects to the rear from the driving shaft 34 and from the machine frame 10. A support comprising spacer bolts 38 and a carrying plate 40 is attached on the rear side of the frame and carries a power cylinder 42, by means of the piston rod 44 of which the push rod 26 can be axially shifted. As a result, the slide members with former portions 12 are moved radially via the links 28 and 30.

The push rod 26 is connected to a piston rod 44 so as to be moved axially thereby but so that the push rod 26 can rotate relative thereto. This coupling includes a bushing 46 fixed to the piston rod 44 by suitable means such as screws. The coupling between the piston rod 44 and the push rod 26 includes an axial thrust bearing wherein a washer 52 is fixedly held onto the end of push rod 26 by a nut 53. Spaced from the washer 52 are a pair of flange members 48 and 50 which are fixedly connected to the bushing 46 and the piston rod 44, respectively. The flanges 48 and 50 are separated from the washer 52 by suitable roller bearings 55 and 57, respectively. Thus, the rod 26 will move axially with the piston rod 44 but will also rotate relative thereto. The righthand portion of bushing 46 forms the surface of an abutment member, the purpose of which will be described below.

On the rear of the housing 10, a carrying plate 56 is attached by means of screws 54. The push rod 26 is guided through a central bore of the plate 56. The lat ter however constitutes a final stop for the abutment member surface of bushing 46, whenever the piston rod 44 is completely extended to the right. In this position of the push rod,2 6, defined by the abutment of the bushing 46 on-the plate 56, the links 28 and 30 assume the radial position shown in FIG. 2a, and the former 12 is spread to a maximum, so that the largest possible cross-section for the coil will result during winding.

The narrowest position of the former, which is shown in FIG. 2b, in which the wound coil or group of coils is taken off the former, is determined by the abutment of the bushing 46 against the carrying plate 40 whenever the piston rod 44 is pulled back completely to the left. Winding devices having inner and outer positions are previously known. As can be seen, there is in this case only one winding position in which the bushing 40 abuts the plate 56 and the former 12 is expanded. The coils or groups of coils wound within the position of the former are large enough in cross-section to be disposed radially outside in the grooves of a stator. Equally large coils however, whenever they are inserted radially inside into the grooves of the stator, project relatively far out of the stator with their winding heads on the front side. In order to be able to use the same winding apparatus without major alterations to wind coils which have a somewhat smaller cross-section, which coils will then constitute the radially inside layers in the stator, one or more movable stops in the case of the present embodiment two differently dimensioned stops 58 and 60are attached to the plate 56. These stops are shiftable radially, guided between the plate 56 and a plate 64, and connected with the former by way of a bushing or an annular flange 62. One power cylinder 66 provides the motive power for each stop, the piston rod of which power cylinder is connected with the pertinent stop 58 M60 by wayof a T-groove connection.

Whenever both stops 58 and 60 are pulled back to their radial outside positions, then on operation of the power cylinder 42, the bushing 46 moving with the push rod 26, can be shifted to the right until it abuts against the plate 56. If, however, one of the stops 58 or 60 assumes its radially inside position, then the bushing 46 moving to the right abuts against the pertinent stop, and the push rod 26 is thereby blocked against any further movement to the right. Since the stops 58 and 60 are of different thicknesses, whenever the bushing 46 has moved against the pertinent stop, this results in different axial positions of the push rod 26, and thus also of the links 28, 30 and of the former portions 12. FIGS. 2c and 2d show these two intermediate positions, wherein the former 12 is in a smaller cross-section of the coil than in the fully expanded position of FIG. 2a, but in a larger cross-section of the coil than in FIG. 2b. For the purpose of drawing-off from the former coils wound in one of these intermediate positions, the former is also moved into its smallest position according to FIG. 2b by the power cylinder 42 pulling back the bushing 46 from the stop 58 and 60 to its rear abutment against the carrier plate 40.

It is not essential to the function of the stops 58 and 60 in which angular position they are disposed about the axis of rod 26 in relation to one another. For example, the stops can be attached, as shown in FIGS. 2a-d, opposite in relation to the push rod 26. But they can also lie at a right angle or some other angle in relation to one another as shown in FIG. 4.

So that as large as possible a stop face can be obtained, the stops 58 and 60 radially inside are cut out essentially in the shape of a semicircle so that they encircle the push rod 26 in their radially moved operating position.

It is apparent that instead of several individual stops, a multi-step stop can also be used. Oblique surfaces or similar control measures can be provided for the shiftving drive of the push rod 26. It is also possible to provide a continuously variable means such as a stop member with an oblique inclined surface. Instead of the drive unit which uses a push rod or links as shown in the drawing, some other mechanical or pressure agent operated drive could also be used.

Although the invention has been described in considerable detail with respect to a preferred embodiment, it will be apparent that the invention is capable of numerous modifications and variations apparent to those skilled in the art without departing from the spirit and scope of the invention.

I claim:

1. An apparatus for winding coils for stators of electrical machines, comprising: a frame, a hollow shaft rotatably mounted in the frame, a face plate means fixed to the hollow shaft and extending radially outwardly therefrom, means formed on said face plate for providing at least two radially extending guide surfaces, a sliding member on each guide surface, a former portion fixedly mounted on each sliding member to move radially therewith, a connecting means connecting each guide surface to its respective sliding member, each said connecting means including means for supporting its respective sliding member on its respective guide surface so as to form a driving connection from said shaft via said face plate and said connecting means to said sliding member and to its respective former, said connecting means further including means for mounting its respective sliding member so as to constrain the sliding member to move radially only in a plane perpendicular to the axis of rotation of the shaft, the former formed by the former protions thus receiving coil windings thereon about its periphery and being movable by said radial movement in said plane to at least two winding crosssections and a smaller cross-section for drawing off a wound coil, a rod extending through the said hollow shaft to a position between said former portions, a rod mounting means for mounting the rod for axial movement relative to the shaft and for rotatable movement with the shaft, at least one link pivotally connecting the rod to each former portion such that upon axial movement of the rod the links pivot and urge their respective former portions to move radially by their sliding members sliding on their respective facing plate means guide surfaces, whereby the axial position of the rod determines the radial position of the former porjecting radially out from said axis and movable axially tions and hence determines the former cross-section, and including stop means for positively stopping the rod to locate'the position thereof corresponding to said at least two cross-sections.

2. An apparatus according to claim 1, said links comprising a pair of parallel links for each former portion, each pair pivotably connected at one of their ends to the rod and at the other of their ends to the outwardly slidable former portion or its slidable member.

3. An apparatus according to claim 1, further including:

power means for moving the rod axially between a first end position at which the former portions are drawn towards each other in said drawing-off position, and a second end position at which the former portions are moved away from each other to the largest of said winding positions, and said stop means including means for stopping the rod be- 7 tween said end positions at at least one other winding position. 4. An apparatus according to claim 3, said power means being a reciprocating power piston and cylinder unit, and said rod mounting means including means connecting the rod to the piston and cylinder unit for with the rod, and at least one stop member movable into and out of the path of the abutment member to stop the rod between said end positions.

6. An apparatus according to claim 5, said abutment member extending completely about the axis of the rod, and said stop member having a semicircular opening at its end to embrace half of the circumference of the rod as the portion of the stop member adjacent said recess is engaged by the abutment member for about the rod.

7. An apparatus to claim 5, including a pair of stop members, each movable into and out of the path of the abutment member from a different direction and each capable of stopping the abutment member and hence the rod at a different'winding position between said end positions.

8. An apparatus according to claim 5, each said link comprising a pair of parallel links for each former portion, each pair pivotably connected at one of their ends to the rod and to the other of their ends to the outwardly slidable former portion or its slidable member. 

1. An apparatus for wiNding coils for stators of electrical machines, comprising: a frame, a hollow shaft rotatably mounted in the frame, a face plate means fixed to the hollow shaft and extending radially outwardly therefrom, means formed on said face plate for providing at least two radially extending guide surfaces, a sliding member on each guide surface, a former portion fixedly mounted on each sliding member to move radially therewith, a connecting means connecting each guide surface to its respective sliding member, each said connecting means including means for supporting its respective sliding member on its respective guide surface so as to form a driving connection from said shaft via said face plate and said connecting means to said sliding member and to its respective former, said connecting means further including means for mounting its respective sliding member so as to constrain the sliding member to move radially only in a plane perpendicular to the axis of rotation of the shaft, the former formed by the former protions thus receiving coil windings thereon about its periphery and being movable by said radial movement in said plane to at least two winding crosssections and a smaller cross-section for drawing off a wound coil, a rod extending through the said hollow shaft to a position between said former portions, a rod mounting means for mounting the rod for axial movement relative to the shaft and for rotatable movement with the shaft, at least one link pivotally connecting the rod to each former portion such that upon axial movement of the rod the links pivot and urge their respective former portions to move radially by their sliding members sliding on their respective facing plate means guide surfaces, whereby the axial position of the rod determines the radial position of the former portions and hence determines the former crosssection, and including stop means for positively stopping the rod to locate the position thereof corresponding to said at least two cross-sections.
 2. An apparatus according to claim 1, said links comprising a pair of parallel links for each former portion, each pair pivotably connected at one of their ends to the rod and at the other of their ends to the outwardly slidable former portion or its slidable member.
 3. An apparatus according to claim 1, further including: power means for moving the rod axially between a first end position at which the former portions are drawn towards each other in said drawing-off position, and a second end position at which the former portions are moved away from each other to the largest of said winding positions, and said stop means including means for stopping the rod between said end positions at at least one other winding position.
 4. An apparatus according to claim 3, said power means being a reciprocating power piston and cylinder unit, and said rod mounting means including means connecting the rod to the piston and cylinder unit for reciprocating axial movement therewith and for rotatable movement about its axis, the rod thus being free to rotate with the former.
 5. An apparatus according to claim 4, said stop means including at least one abutment member projecting radially out from said axis and movable axially with the rod, and at least one stop member movable into and out of the path of the abutment member to stop the rod between said end positions.
 6. An apparatus according to claim 5, said abutment member extending completely about the axis of the rod, and said stop member having a semi-circular opening at its end to embrace half of the circumference of the rod as the portion of the stop member adjacent said recess is engaged by the abutment member for 180* about the rod.
 7. An apparatus to claim 5, including a pair of stop members, each movable into and out of the path of the abutment member from a different direction and each capable of stopping the abutment member and hence the rod at a different winding position between said end positions.
 8. An apparatus accorDing to claim 5, each said link comprising a pair of parallel links for each former portion, each pair pivotably connected at one of their ends to the rod and to the other of their ends to the outwardly slidable former portion or its slidable member. 